For the 600th episode of WTF, Marc goes back to someone who was there at the beginning. Sam Seder and Marc retrace the path of their contentious friendship, which reached its combative apex right before WTF was created. Also, a surprise guest who is staying in the hotel room next to Marc drops by for an impromptu chat. This episode is sponsored by the new movie The D Train, Trunk Club, 1-800 Flowers and Warby Parker.